1) Field
Embodiments of the present invention pertain to the field of semiconductor processing and, in particular, to methods of forming deep trenches in substrates.
2) Description of Related Art
Conventional deep reactive ion etching or deep silicon etch processes often exhibit some level of undercut in the etch profile. For example, in some processes, chemical species such as fluorine radicals etch a via or a trench sidewall laterally (in addition to the desired vertical etch pathway) and in some case may cause significant undercut.